I am working on a problem of registration of a particular type of medical imaging. To do this, I have to extract extrinsic markers automatically from the images.
Take this image as an example:
I have to detect those white little cicles in the bottom, knowing that the color is not always the same.
I used fastNlMeansDenoising and blur to denoise image, then I've tried some edge detection techniques, in particular Canny edge detector, I used trackbars to try to find the best thresholds, but i can't find commun ones that will work on all images.